N = int(input())
test = input()
if len(test) == 1:
    A = [int(test)]
    for _ in range(N-1):
        A += [int(input())]
    L = [A[0]+A[1], A[0]+A[2], A[1]+A[2]]
    L.sort(reverse=True)
    if L[0] > L[1]:
        print(L[1])
    else:
        print(L[2])
else:
    print("assert")